Sonic Eraser is a "lost" puzzle video game that is available to owners of the Sega Meganet, a modem for the Sega Mega Drive in Japan. Other than Sonic's sprite, there is little that relates the game with the rest of the Sonic franchise.
The game's availability is quite rare due to its Japan-only release and the lack of success of the Sega Meganet. However, a ROM image has been made available on the internet in 2004.
In the versus mode, when a player gets a combination of three consecutive lineups of pieces, that player attacks the other player. The player momentarily takes control of the other player's pieces.
The game offers four unique modes of gameplay. Normal Mode is an "endless mode" in which the player accumulates points endlessly. The better the player performs, the higher their level will rise and the speed at which clusters fall increases. Doubt Mode is the same as normal mode except that white squares will never fall.[clarification needed] Instead, a single shape from almost every cluster will turn into a white square when it hits the ground. Round Mode is a puzzle mode consisting of ten stages. Each stage has a bunch of swirl shapes interspersed with other normal shapes. Just like the other shapes, the swirls disappear when paired.
The object is to clear them all from the play field by eliminating the shapes between them under the time limit. Lastly is Block Mode, which has clusters stand on-end, allowing for massive chain reactions.